It's happening to a lot of hatcheries- Covid made delays in the post office. Probably the reason why Ideal now sells hatching eggs again when they stopped selling them for a long time before Covid. I'm guessing the reason you ordered from a hatchery in Iowa rather than Privett in New Mexico is because you wanted a lower minimum order or breeds that were offered at MM but not Privett.
My friend ordered from MM about 15 years ago and all made it healthy. She was in AZ. McMurray was also hit with Avian flu last year which affected one of their barns so they may have had a smaller flock to restart with which could lead to inbreeding consequences. I think those who live closer to Iowa will certainly have a better outcome.